Levallorphan

Levallorphan (INN, BAN) (brand names Lorfan, Naloxifan, Naloxiphan), also known as levallorphan tartate (USAN), is an opioid modulator of the morphinan family used as an opioid analgesic and opioid antagonist/antidote. It acts as an antagonist of the μ-opioid receptor (MOR) and as an agonist of the κ-opioid receptor (KOR), and as a result, blocks the effects of stronger agents with greater intrinsic activity such as morphine whilst simultaneously producing analgesia.